@article{CMH_1984__59_139986,
     author = {R.V. Gurjar and A.R. Shastri},
     title = {The fundamental group at infinity of affine surfaces.},
     journal = {Commentarii mathematici Helvetici},
     pages = {459--484},
     publisher = {mathdoc},
     volume = {59},
     year = {1984},
     zbl = {0594.14015},
     url = {http://geodesic.mathdoc.fr/item/CMH_1984__59_139986/}
}